Sprint superstar Usain Bolt brought the world championships to a thrilling climax today. On the last night of action in Daegu, South Korea, his Jamaican team smashed the world 4 x100 metres relay record. It was Bolt's second gold of the worlds after winning the 200 metres crown and marked a fairytale ending for the sprinter. The second day of the championships saw his 100 metres dream shattered when he false-started. Jamaica's team of Nesta Carter, Michael Frater, Yohan Blake and Bolt got off to a flyer and never looked like being caught, Bolt stretching every sinew to cross the line in 37.04 seconds to beat their previous world record of 37.10 set in the final of the Beijing Olympics. France took silver and St Kitts and Nevis bronze. Main challengers the United States failed to finish after Darvis Patton tumbled to the ground and could not get the baton to Walter Dix who was running the anchor leg. Elsewhere on the track, Mo Farah ensured Olympic hosts Britain ended the worlds on a high with 5,000 metres gold. Farah won a thrilling battle down the home stretch to take gold, putting behind him the frustration of just missing out on the 10,000 metres title.